Stapling device with articulating tool assembly

ABSTRACT

A surgical stapling device includes a mounting assembly that is pivotably supported on a distal portion of a housing about a pivot axis and movable between a non-articulated position and an articulated position. A drive assembly includes a flexible body having a working end and an articulation assembly includes an active articulation link that is coupled to the mounting assembly and movable between a retracted position and an advanced position to pivot the mounting assembly about the pivot axis. A gate assembly defines a channel that receives the flexible body of the drive assembly. The active articulation link is positioned to engage the gate assembly when the active articulation link moves between its retracted and advanced positions to move the gate assembly to a position to increase the bending radius of the flexible body of the drive assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 62/828,217 filed Apr. 2, 2019, the entire disclosure of which is incorporated by reference herein.

BACKGROUND 1. Technical Description

The present disclosure is directed to surgical stapling devices, and more particularly, to surgical stapling devices with tool assemblies that are supported on the stapling device for articulation.

2. Background of Related Art

Surgical stapling devices configured for endoscopic or laparoscopic use include an elongate body having a proximal portion and a distal portion, and a tool assembly supported on the distal portion of the elongate body. Typically, the tool assembly is supported by a pivot member that facilitates articulation of the tool assembly in relation to the elongate body. In some stapling devices, the tool assembly is limited to about 45 degrees of articulation about the pivot member in one or both directions.

Known stapling devices include an articulation mechanism that extends through a body of the stapling device and has a distal end that is coupled to the tool assembly. Typically, the articulation mechanism includes one or more articulation links that are movable along a longitudinal axis of the body of the stapling device to pivot the tool assembly about an axis transverse to the longitudinal axis.

In known stapling devices, the tool assembly is unstable when the tool assembly is in a non-articulated position, i.e., the position in which a longitudinal axis of the tool assembly is aligned with a longitudinal axis the elongate body. As such, the tool assembly becomes misaligned with the longitudinal axis of the body as the tool assembly is moved within a body cavity.

A continuing need exists in the art for a stapling device that includes a tool assembly that can be articulated over a wider range of angles and is stable in all positions of articulation including a non-articulated position.

SUMMARY

One aspect of the disclosure is directed to a surgical stapling device including a body portion, a mounting assembly, a drive assembly, an articulation assembly, and a gate assembly. The housing includes a proximal portion and a distal portion. The mounting assembly is pivotably supported on the distal portion of the housing about a pivot axis and movable between a non-articulated position and an articulated position. The drive assembly includes a flexible body having a working end. The drive assembly is movable within the housing from a retracted position to an advanced position. The articulation assembly includes an active articulation link having a proximal portion and a distal portion that is coupled to the mounting assembly. The active articulation link is movable between a retracted position and an advanced position to pivot the mounting assembly about the pivot axis. The gate assembly defines a channel that receives the flexible body of the drive assembly, wherein the active articulation link is positioned to engage the gate assembly when the active articulation link moves between its retracted and advanced positions to move the gate assembly to a position to increase the bending radius of the flexible body of the drive assembly.

In embodiments, the gate assembly is pivotably supported within the housing.

In some embodiments, the gate assembly includes an upper gate and a lower gate.

In certain embodiments, each of the upper and lower gates includes an elongate body and a U-shaped member supported on a distal portion, wherein the U-shaped members of the upper and lower gates define the channel.

In embodiments, the elongate body of each of the upper and lower gates includes a pivot member that pivotably connects the upper and lower gates within the housing.

In some embodiments, each of the U-shaped members of the upper and lower gates includes an engagement member, wherein the active articulation link is positioned to engage one of the engagement members of the upper or lower gates.

In certain embodiments, the articulation link includes a passive articulation link having a distal portion coupled to the mounting assembly such that pivotal movement of the mounting assembly about the pivot axis causes movement of the passive articulation link between retracted and advanced positions within the housing.

In embodiments, a blowout plate is supported on each side of the elongate body of the drive assembly. Each of the blowout plates includes a distal end supported on the mounting assembly at a position distally of the pivot axis and a proximal end supported within the housing proximally of the pivot axis.

In some embodiments, a stabilization mechanism is engaged with the active and passive articulation links and is configured to urge the mounting assembly to the non-articulated position.

In embodiments, a tool assembly is supported on the mounting assembly.

In some embodiments, the tool assembly includes a cartridge assembly and an anvil assembly.

In certain embodiments, the tool assembly is configured to receive the working end of the device assembly.

In embodiments, the distal portion of the active articulation link includes a hook and the mounting assembly includes a finger, wherein the hook is positioned to engage the finger when the active articulation link is moved towards the advanced position to assist in articulation of the mounting assembly.

In some embodiments, the active articulation link includes a first active articulation link and a second active articulation link that is pivotably coupled to the first active articulation link.

In certain embodiments, the distal portions of each of the active articulation link and the passive articulation link include a hook and the mounting assembly includes fingers, wherein the hooks are positioned to engage a respective one of the fingers when the respective active and passive articulation links are moved towards the advanced position to assist in articulation of the mounting assembly.

In embodiments, the active articulation link includes a first active articulation link and a second active articulation link that is pivotably coupled to the first active articulation link, and the passive articulation link includes a first passive articulation link and a second passive articulation link that is pivotably coupled to the first passive articulation link.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the presently disclosed surgical stapling device are described herein below with reference to the drawings, wherein:

FIG. 1 is a side perspective view of an exemplary embodiment of the presently disclosed surgical stapling device with a tool assembly of the stapling device in a non-articulated position;

FIG. 2 is a side perspective view of the surgical stapling device shown in FIG. 1 with the tool assembly of the stapling device in an articulated position;

FIG. 3 is an enlarged view of the indicated area of detail shown in FIG. 1;

FIG. 4 is an enlarged view of the indicated area of detail shown in FIG. 2;

FIG. 5 is a side perspective exploded view of a reload of the stapling device shown in FIG. 1 including the tool assembly;

FIG. 5A is a cross-sectional view taken along section line 5A-5A of FIG. 5;

FIG. 6 is a side perspective view of articulation links of an articulation assembly of the reload shown in FIG. 5;

FIG. 7 is a side perspective view of a proximal portion of the reload shown in FIG. 5 with an outer tube and the anvil assembly removed and the tool assembly in the non-articulated position;

FIG. 8 is an enlarged view of the indicated area of detail shown in FIG. 7;

FIG. 9 is a side perspective view of the reload shown in FIG. 5 assembled in the non-articulated position with the outer tube of the reload removed;

FIG. 10 is a side perspective view of a stabilization system of the reload assembly shown in FIG. 5;

FIG. 11 is an enlarged view of the indicated area of detail shown in FIG. 9;

FIG. 12 is an enlarged view of the indicated area of detail shown in FIG. 7;

FIG. 13 is a perspective view from the distal end of a distal portion of a housing half-section of a proximal body portion of the reload shown in FIG. 5 with a gate assembly supported in the housing half-section;

FIG. 14 is an exploded side perspective view of the gate assembly of the reload shown in FIG. 5;

FIG. 15 is a side perspective view from the distal end of the gate assembly of the reload shown in FIG. 5;

FIG. 16 is a side perspective view from the proximal end of the gate assembly of the reload shown in FIG. 5;

FIG. 17 is a cross-sectional view taken along section line 17-17 of FIG. 7;

FIG. 18 is an enlarged view of the indicated area of detail shown in FIG. 17;

FIG. 19 is a cross-sectional view taken along section line 19-19 of FIG. 8;

FIG. 20 is a top view of the proximal portion of the reload shown in FIG. 6 with the outer tube and a housing half-section removed and the tool assembly in the non-articulated position;

FIG. 21 is a top view of the proximal portion of the reload shown in FIG. 6 with the outer tube and a housing half-section removed and the tool assembly in the articulated position;

FIG. 22 is a side perspective view of the proximal end of the tool assembly and the distal end of the proximal body portion with the drive assembly removed and the tool assembly in an articulated position;

FIG. 23 is a cross-sectional view through the proximal end of the tool assembly and the distal end of the proximal body portion with the drive assembly removed and the tool assembly in an articulated position; and

FIG. 24 is a top view of the proximal end of the tool assembly and the distal end of the proximal body portion with the tool assembly in an articulated position.

DETAILED DESCRIPTION OF EMBODIMENTS

The presently disclosed device will now be described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. However, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure and may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure.

In this description, the term “proximal” is used generally to refer to that portion of the device that is closer to a clinician, while the term “distal” is used generally to refer to that portion of the device that is farther from the clinician. In addition, the term “endoscopic” is used generally used to refer to endoscopic, laparoscopic, arthroscopic, and/or any other procedure conducted through small diameter incision or cannula. Further, the term “clinician” is used generally to refer to medical personnel including doctors, nurses, and support personnel.

Referring to FIGS. 1-4, the presently surgical stapling device is shown generally as stapling device 10 and includes a handle assembly 12, an adapter assembly 14, and a tool assembly 16. In embodiments, the tool assembly 16 forms part of a reload assembly 18 that includes the tool assembly 16 and a body portion 20 that has a proximal portion 22 and a distal portion 24. The adapter assembly 14 and the body portion 20 of the reload 18 define a longitudinal axis “X” (FIG. 2). The proximal portion 22 of the body portion 20 of the reload 18 is adapted to be coupled to a distal portion 26 of the adapter assembly 14 and the distal portion of the body portion 20 is pivotally coupled to the tool assembly 16 about a pivot axis “Y” (FIG. 2) that is substantially perpendicular to the longitudinal axis “X”. The tool assembly 16 is pivotal between a non-articulated position (FIG. 1) in which the tool assembly 16 is aligned with the longitudinal axis “X” and articulated positions in which the tool assembly 16 defines an acute angle with the longitudinal axis “X”. It is envisioned that the tool assembly 16 may be connected directly to the distal portion 26 of the adapter assembly 14 and need not form part of a reload assembly 18.

In embodiments, the handle assembly 12 is powered and includes a stationary handle 30 and actuation buttons 32 that can be actuated to control various functions of the stapling device 10 including approximation and firing of the tool assembly 16. U.S. Pat. No. 9,055,943 (“the '943 Patent”) discloses a surgical stapling device having a powered handle assembly, an adapter assembly, and a tool assembly that is releasably coupled to the adapter assembly. The '943 Patent is incorporated herein by reference in its entirety. Alternately, the handle assembly 12 can be manually actuated such as described in U.S. Pat. No. 5,865,361 (“the '361 Patent”) which is incorporated herein by reference in its entirety.

Referring to FIGS. 3-5, the tool assembly 16 includes an anvil assembly 40 and a cartridge assembly 42. In embodiments, the cartridge assembly 42 includes a staple cartridge 42 a and channel 42 b and is pivotally coupled to the anvil assembly 40 between an open position and a clamped position. Alternatively, it is envisioned that the cartridge assembly 42 can be stationary and the anvil assembly 40 can be movable between the open and clamped positions such as described in the '361 Patent.

Referring to FIG. 5, the body portion 20 of the reload assembly 18 (FIG. 1) includes an outer casing 44, a first housing half-section 46, a second housing half-section 48, a mounting assembly 50, first and second active articulation links 52, 54, first and second passive articulation links 56, 58, a drive assembly 60, an articulation stabilization mechanism 62, and a gate assembly 64. The drive assembly 60 of the reload assembly 18 includes a flexible body 68 having a working end 66. The working end 66 is movable through the tool assembly 16 to actuate the tool assembly 16 as is known in the art. For a more detailed description of the structure and operation of the drive assembly 60, see the '361 Patent. The first and second housing half-sections 46, 48, respectively, are secured together to define a housing 70 that supports the articulation links and the articulation stabilization mechanism 62 as described in further detail below.

The mounting assembly 50 (FIG. 19) includes a first mounting portion 72, a second mounting portion 74, a first coupling member 76, and a second coupling member 78. The first mounting portion 72 defines a longitudinal slot 72 a and includes a pivot member 80 and internal fingers 81. The internal fingers 81 are positioned to engage the articulation links 52 and 56 during articulation of the tool assembly 16 as discussed in further detail below. The first coupling member 76 has a first end that defines an opening 76 a that receives the pivot member 80 and a second end 76 b that is received within a recess 82 defined in a distal end of the first housing half-section 46 of the reload 18 such that the first coupling member 76 pivotably secures the tool assembly 16 to the first housing half-section 46. The pivot member 80 is also received in an opening 40 a (FIG. 5) defined in a proximal end of the anvil assembly 40 to pivotally couple the anvil assembly 40 to the first mounting portion 72 of the mounting assembly 50.

The second mounting portion 74 also includes a pivot member 84 (FIG. 19). The second coupling member 48 has a first end defining an opening 74 a that receives the pivot member 84 of the second mounting portion 74 and a second end that is received within a recess 86 defined within the second housing half-section 48 to pivotally secure the second mounting portion 74 to the second housing half-section 48 of the body portion 20 of the reload assembly 18. The outer casing 44 of the proximal portion 22 of the reload 18 is positioned about the first and second housing half-sections 46, 48 to prevent separation of the first and second housing half-sections 46, 48 from one another and to prevent the second ends of the first and second coupling members 76, 78 from moving from within the recesses 82, 86, respectively.

The second mounting portion 74 includes distal extensions 90 that define a slot 92 that is aligned with the slot 72 a in the first mounting portion 72. The distal extensions 90 are received in a proximal end of the anvil assembly 40 (FIG. 18) and define openings 94. The proximal ends of the anvil assembly 40 and the channel 42 b of the cartridge assembly 42 also define openings 96 that are aligned with the openings 94 in the second mounting portion 74 of the mounting assembly 50. The openings 94 and 96 receive pivot members (not shown) to secure the anvil assembly 40 to the second mounting portion 74 and to pivotably secure the cartridge assembly 42 to the anvil assembly 40 about the pivot axis “Y” (FIG. 19).

Referring to FIGS. 3-5, the first and second mounting portions 72, 74, respectively, are secured together using pins or rivets to fixedly secure the tool assembly 16 to the mounting assembly 50. For a more detailed description of the interconnection between the mounting assembly 50 and the tool assembly 16, see the '361 Patent.

Referring to FIGS. 5-8, the first and second active articulation links 52, 54, respectively, are supported between the first and second housing half-sections 46, 48 on opposite sides of the housing 70 of the body portion 20. The first active articulation link 52 is elongate and includes a proximal portion 100 and a distal portion 102. The proximal portion 100 is adapted to engage an articulation drive mechanism (not shown) located within the adapter assembly 14 to translate motion of the drive mechanism into longitudinal movement of the articulation link 52. In embodiments, the proximal portion 100 may include a transverse extension 104 that is positioned to engage the articulation drive mechanism (not shown) of the adapter assembly 14 as known in the art. Alternately, it is envisioned that the active articulation link 52 can engage the drive mechanism (not shown) of the adapter assembly 14 using a variety of different configurations or coupling devices. The distal portion 102 of the articulation link 52 includes an inner cam surface 106, a hook 108, and an opening 110. The cam surface 106 forms the inner surface of the hook 108 and is positioned to support one side of the drive assembly 60 as described in further detail below. The cam surface 106 defines a curved surface that extends towards the longitudinal axis “X” in a distal direction.

The function of the hook 108 will be described in further detail below. The opening 110 receives a pivot member 112 that is supported on the second active articulation link 54 to pivotally couple the second active articulation link 54 to the distal portion 102 of the first active articulation link 52.

The second active articulation link 54 also includes a distal portion that defines an opening 114. The opening 114 receives a pivot member 116 (FIG. 18) that is supported on a first side of the mounting assembly 50 at a position transversely offset from the pivot axis “Y” (FIG. 2) to pivotally secure the second active articulation link 54 to the mounting assembly 50. Although not shown, the first active articulation link 52 is confined to linear movement within the housing 50 of the body portion 20 of the reload assembly 18. Pivotally coupling the second articulation link 54 between the first articulation link 52 and the mounting assembly 50 increases the range of articulation of the tool assembly 16 in relation to the adapter assembly 14 that is possible. When the first active articulation link 52 is moved longitudinally within the body portion 20 of the reload 18, the second active articulation link 54 is advanced and pivoted about the pivot member 112 to cause pivotal movement of the tool assembly 116 about the axis “Y” (FIG. 2). It is noted that the length of the second active articulation link 54 is substantially shorter than the length of the first active articulation link 52 such that the links 52 and 54 do not protrude outwardly of the mounting assembly 50 beyond a predetermined distance when the mounting assembly 50 and tool assembly 16 are articulated.

The first active articulation link 52 also defines a bushing engagement surface 118. In embodiments, the bushing engagement surface 118 is positioned between the proximal and distal portions 100, 102 and is positioned to interact with the stabilization mechanism 62 (FIG. 5) to provide stability to the tool assembly 16 in the non-articulated position of the tool assembly as described in detail below.

The first passive articulation link 56 includes an elongate body having a proximal portion 120 and a distal portion 122. The proximal portion 120 includes a bushing engagement surface 124 that is positioned to interact with the stabilization mechanism 62 (FIG. 5) to provide stability to the tool assembly 16 in the non-articulated position of the tool assembly 16 as described in detail below. The distal portion 122 of the articulation link 56 includes an inner cam surface 126, a hook 128, and an opening 130. The cam surface 126 forms the inner surface of the hook 128 and is positioned to engage one side of the drive assembly 60 as described in further detail below. The cam surface 126 defines a curved surface that extends towards the longitudinal axis “X” in a distal direction. The function of the hook 128 will be described in further detail below. The opening 130 receives a pivot member 132 that is supported on the second passive articulation link 58 to pivotally couple the second passive articulation link 58 to the distal portion 122 of the first passive articulation link 52.

The second passive articulation link 58 also includes a distal portion that defines an opening 134. The opening 134 receives a pivot member 136 that is supported on a second side of the mounting assembly 50 to pivotally secure the second passive articulation link 58 to the mounting assembly 50 at a position transversely offset from the pivot axis “Y” (FIG. 2). Although not shown, the first passive articulation link 56 is confined to linear movement within the housing 50 of the body portion 20 of the reload assembly 18. As described above in regard to second active articulation link 54, pivotally coupling the second passive articulation link 58 between the first passive articulation link 56 and the mounting assembly 50 increases the range of articulation of the tool assembly 16 in relation to the adapter assembly 14. As discussed above in regard to the second active articulation link 54, the length of the second passive link 58 is substantially shorter than the length of the first passive articulation link 56 such that the links 56 and 58 do not protrude outwardly of the mounting assembly 50 beyond a predetermined distance.

Referring also to FIGS. 9-12, the articulation stabilization system 62 includes a biasing mechanism 140 including a slide member 142 and a plurality of springs 144. In embodiments, the slide member 142 is substantially annular and includes a first half-section 146 and a second half-section 148. The slide member 142 is slidably positioned within a recess 150 defined in an outer surface of the housing 70 of the body portion 20 of the reload assembly 18. The slide member 142 includes distally extending spring mounting tabs 150, a first proximally extending bushing 152, and a second proximally extending bushing 154. In embodiments, each of the half-sections 146, 148 of the slide member 142 includes respective side wall recesses 160 and side wall extensions 162 that mesh to form the annular slide member 142.

In embodiments, the springs 144 are coil springs that have a proximal portion that is received about the spring mounting tabs 150 of the slide member 142. Each of the springs 144 is positioned within a respective pocket 164 defined in the housing 22 to urge the slide member 142 distally about the housing 22. The first bushing 152 of the slide member 142 is received within the notch 118 of the first active articulation link 52 to urge the articulation link 52 proximally to a position in which the tool assembly 16 is in the non-articulated position. When the articulation link 52 is positioned such that the tool assembly 16 is in the non-articulated position, the springs 144 are in an unbiased state with the bushing 152 positioned within the notch 118 and engaged with the articulation link 52. In addition, bushing 154 is positioned within the surface 124 in engagement with the first passive articulation link 56 to urge the articulation link 56 proximally to a position in which the tool assembly 16 is also in the non-articulated position. When the articulation link 56 is positioned such that the tool assembly 16 is in the non-articulated position, the springs 144 are in an unbiased state with the bushing 154 engaged positioned within the surface 124 of the articulation link 56.

For a more detailed description of the presently disclosed stabilization system 62, see U.S. Patent Application No. 62/585,703 (“the '703 Application”) which was filed on Nov. 14, 2017 and is incorporated herein by reference in its entirety.

Referring also to FIGS. 13-16, the gate assembly 64 includes an upper gate 170 and a lower gate 172. Each of the upper and lower gates 170, 172, respectively, includes an elongate body 174 and a U-shaped member 176. When the upper and lower gates 170, 172 are assembled, the gates 170, 172 define a channel 178. The channel 178 is dimensioned to receive and allow passage of the flexible body 68 of the drive assembly 60 as the drive assembly 60 is moved between retracted and advanced positions to approximate and fire staples from the stapling device 10 as is known in the art.

The elongate body 174 of each of the gates 170, 172 includes a pivot member 180 that is pivotally coupled to an inner wall of the housing 70 of the body portion 20 of the reload assembly 18 to axially fix the gates 170, 172 within the housing 70 while permitting pivotal movement of the gates 170, 172 within the housing 70. Each of the U-shaped members 176 of the gates 170, 172 may have an engagement member 182 that is positioned to abut the cam surfaces 106, 126 of the articulation links 52, 56, respectively, as described in further detail below. In use, the gates 170, 172 increase a bending radius of the flexible body 68 of the drive assembly 60 when the tool assembly 16 is in an articulated position in relation to the adapter assembly 14.

Referring again to FIGS. 5 and 8, the reload assembly 18 also includes blow out plates 184. The blowout plates 184 are positioned on opposite sides of the flexible body 68 of the drive assembly 60 and extend from a position distal of the pivot axis “Y” (FIG. 2) to a position proximal of the pivot axis “Y”. In embodiments, distal ends of the blow out plates 184 are secured within a slot 186 (FIG. 8) in the mounting assembly 50. In some embodiments, a proximal end of the blowout plates 184 includes a transverse portion 188 that is received within a recess 190 (FIG. 8) within the housing 70 of the body portion 20 to allow the proximal end of the blow out plates 184 to slide within the housing 70. The sliding movement allows the blowout plates 184 to adjust accordingly when the radius of curvature changes as the tool assembly 16 is articulated about the pivot axis “Y”. The blowout plates 184 are positioned to obstruct outward bulging of the flexible body 68 of the drive assembly 60 during approximation and firing of the stapling device 10. See the '361 patent for a more detailed description of the blowout plates 184.

Referring to FIGS. 17-20, when the tool assembly 18 of the reload 18 is in a non-articulated position, the flexible body 68 of the drive assembly 60 extends along the longitudinal axis “X” of the body portion 20 of the reload 18 between the blowout plates 184 and through the channel 178 of the gate assembly 64. In addition, the articulation links 52 and 56 are urged to neutral positions by the stabilization mechanism 62. In their neutral positions, the cam surface 106, 128 of the articulation links 52, 56 are positioned in engagement with outer walls of the blowout plates 184 and the gates assembly 64 is positioned such that the channel 178 defines by the gate assembly 64 is aligned with the longitudinal axis “X”. It is noted that the engagement members 182 of the gates 170, 172 of the gate assembly 64 are positioned towards a proximal end of the cam surfaces 106, 126. As discussed above, the cam surfaces 106, 126 define curved surfaces that extend towards the longitudinal axis “X” in a distal direction.

Referring to FIGS. 21-23, when the active articulation link 52 is advanced in the direction indicated by arrows “A” in FIG. 21 by actuating the drive mechanism in the adapter assembly 14 (FIG. 1), the first active articulation link 52 advances the second active articulation link 54 to pivot the mounting assembly 50 and the tool assembly 16 about the pivot axis “Y” (FIG. 19). As the tool assembly 16 pivots about the pivot axis “Y”, the second passive articulation link 58 is moved proximally by the pivot member 136 of the mounting assembly 50. As the second passive articulation link 58 is moved proximally, the first passive articulation link 56 which is pivotally coupled to the second passive articulation link 58 also moves proximally in the direction indicated by arrow “B” in FIG. 21.

When the tool assembly 16 is pivoted about the pivot axis “Y”, the flexible body 68 of the drive assembly 60 bends about the pivot axis “Y” (FIG. 19). As discussed above, the gates 170, 172 (FIG. 14) of the gate assembly 64 define a channel 178 that receives the flexible body 68 of the drive assembly 60. When the first passive articulation link 56 is retracted in the direction indicated by arrow “B” in FIG. 21, the cam surface 126 of the first passive articulation link 56 engages the engagement surface 182 of the gate assembly 64 to pivot the gate assembly 64 about the pivot members 180 in the direction indicated by arrow “C” in FIG. 21. As the gate assembly 64 pivots about the pivot members 180, the gate assembly 64 engages the flexible body 68 of the drive assembly 60 to urge the flexible body 68 towards the first active articulation link 52. This increases the bending radius of the flexible body 68 of the drive assembly 60 by relocating the position of the flexible body 68 in a direction opposite to the direction of articulation of the tool assembly 16. As can be seen in FIG. 21, the cam surface 106 of the articulation link 52 provides added support to the outer surface of the flexible body 68 of the drive assembly 60 to prevent buckling of the flexible body 68 when the tool assembly 16 is articulated.

As shown in FIG. 23, as the active articulation link 52 moves distally towards the mounting assembly 50, the hook 108 on the distal portion of the first active articulation link 52 engages the internal finger 81 of the mounting assembly 50 to urge the mounting assembly 50 in the direction of articulation.

When the first active articulation link 52 moves proximally as shown in FIG. 21, the bushing engagement surface 118 of the first active articulation link 52 engages and urges the slide member 142 distally in the direction indicated by arrow “K” against the urging of the springs 144 to compress the springs 144. As described in detail in the '703 application, the spring force of the springs 144 urges the slide member 142 proximally to urge the first active articulation link 52 towards a position in which the mounting assembly 50 is in a non-articulated position.

Referring to FIG. 24, when the active articulation link 52 is retracted in the direction indicated by arrows “D” by actuating the drive mechanism in the adapter assembly 14 (FIG. 1), the first active articulation link 52 retracts the second active articulation link 54 to pivot the tool assembly 16 in an opposite direction about the pivot axis “Y” (FIG. 19). As the tool assembly 16 pivots about the pivot axis “Y” (FIG. 19), the second passive articulation link 58 is moved distally and pivoted about the pivot member 136 of the mounting assembly 50. As the second passive articulation link 58 is moved distally, the first passive articulation link 56 which is pivotally coupled to the second passive articulation link 58 also moves distally in the direction indicated by arrow “E”.

When the tool assembly 16 is pivoted about the pivot axis “Y”, the flexible body 68 of the drive assembly 60 bends about the pivot axis “Y”. As discussed above, the gates 170, 172 (FIG. 14) of the gate assembly 64 define a channel 178 that receives the flexible body 68 of the drive assembly. When the first active articulation link 52 is retracted in the direction indicated by arrow “D” in FIG. 24, the cam surface 106 of the first active articulation link 52 engages the engagement surface 182 of the gate assembly 64 to pivot the gate assembly 64 about the pivot members 180 in the direction indicated by arrow “F”. As the gate assembly 64 pivots about the pivot members 180, the gate assembly 64 engages the flexible body 68 of the drive assembly 60 to urge the flexible body 68 towards the first passive articulation link 52. This increases the bending radius of the flexible body 68 of the drive assembly 60 by relocating the position of the flexible body 68 in a direction opposite to the direction of articulation of the tool assembly 16. Although not shown in FIG. 24, the cam surface 126 of the first passive articulation link 56 supports the outer surface of the blowout plate 184 to provide added support for the flexible body 68 of the drive assembly 60 to prevent buckling of the flexible body 68 when the tool assembly 16 is articulated.

As the first passive articulation link 56 moves distally towards the mounting assembly 50, the hook 128 on the distal portion of the first passive articulation link 56 engages the internal finger 81 of the mounting assembly 50 to urge the mounting assembly 50 in the direction of articulation.

When the first passive articulation link 56 moves distally, the bushing engagement surface 124 of the first passive articulation link 52 engages and urges the slide member 142 against the urging of the springs 144 (FIG. 10) to compress the springs 144. As described in detail in the '703 application, the spring force of the springs 144 urges the slide member 142 proximally to urge the first passive articulation link 56 proximally towards a position in which the mounting assembly 50 is in a non-articulated position.

Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. It is envisioned that the elements and features illustrated or described in connection with one exemplary embodiment may be combined with the elements and features of another without departing from the scope of the present disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the above-described embodiments. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. 

What is claimed is:
 1. A surgical stapling device comprising: a body portion including a housing, a mounting assembly, a drive assembly, an articulation assembly, and a gate assembly, the housing including a proximal portion and a distal portion, the mounting assembly being pivotably supported on the distal portion of the housing about a pivot axis between a non-articulated position and an articulated position, the drive assembly including a flexible body having a working end, the drive assembly being movable within the housing from a retracted position to an advanced position, the articulation assembly including an active articulation link having a proximal portion and a distal portion, the distal portion of the active articulation link being coupled to the mounting assembly and movable between retracted and advanced positions to pivot the mounting assembly about the pivot axis, the gate assembly defining a channel, the flexible body of the drive assembly extending through the channel of the gate assembly, wherein the active articulation link is positioned to engage the gate assembly when the active articulation link moves between its retracted and advanced positions to move the gate assembly to a position to increase a bending radius of the flexible body of the drive assembly.
 2. The stapling device of claim 1, wherein the gate assembly is pivotably supported within the housing.
 3. The stapling device of claim 2, wherein the gate assembly includes an upper gate and a lower gate.
 4. The stapling device of claim 3, wherein each of the upper and lower gates includes an elongate body and a U-shaped member supported on a distal portion, wherein the U-shaped members of the upper and lower gates define the channel.
 5. The stapling device of claim 4, wherein the elongate body of each of the upper and lower gates includes a pivot member, the pivot members pivotably connecting the upper and lower gates within the housing.
 6. The stapling device of claim 5, wherein each of the U-shaped members of the upper and lower gates includes an engagement member, the active articulation link being positioned to engage one of the engagement members of the upper or lower gates.
 7. The stapling device of claim 6, wherein the articulation link includes a passive articulation link, the passive articulation link having a distal portion coupled to the mounting assembly such that pivotal movement of the mounting assembly about the pivot axis causes movement of the passive articulation link between retracted and advanced positions.
 8. The stapling device of claim 7, further including a blowout plate supported on each side of the elongate body of the drive assembly, each of the blowout plates having a distal end supported on the mounting assembly at a position distally of the pivot axis and a proximal end supported within the housing proximally of the pivot axis.
 9. The stapling device of claim 7, further including a stabilization mechanism, the stabilization mechanism being engaged with the active and passive articulation links and being configured to urge the mounting assembly to the non-articulated position.
 10. The stapling device of claim 1, further including a stabilization mechanism engaged with the articulation assembly, the stabilization mechanism being positioned to urge the mounting assembly to the non-articulated position.
 11. The stapling device of claim 1, further including a tool assembly supported on the mounting assembly.
 12. The stapling device of claim 11, wherein the tool assembly includes a cartridge assembly and an anvil assembly.
 13. The stapling device of claim 12, wherein the tool assembly is configured to receive the working end of the device assembly.
 14. The stapling device of claim 1, wherein the distal portion of the active articulation link includes a hook and the mounting assembly includes a finger, and the hook is positioned to engage the finger when the active articulation link is moved towards the advanced position to assist in articulation of the mounting assembly.
 15. The stapling device of claim 14, wherein the active articulation link includes a first active articulation link and a second active articulation link that is pivotably coupled to the first active articulation link.
 16. The stapling device of claim 7, wherein the distal portion of the active articulation link and the passive articulation link each include a hook and the mounting assembly includes fingers, the hooks being positioned to engage a respective one of the fingers when the respective active and passive articulation links are moved towards the advanced position to assist in articulation of the mounting assembly.
 17. The stapling device of claim 7, wherein the active articulation link includes a first active articulation link and a second active articulation link that is pivotably coupled to the first active articulation link, and the passive articulation link includes a first passive articulation link and a second passive articulation link that is pivotably coupled to the first passive articulation link. 